Just got my new 250R today

[ChvyCruzen]

I bought an R off eBay. Its a 310cc flat track set up.

I have a question about the motor. It has AV gas right now mixed at 40:1 and smokes A LOT! I warmed it up and it still smokes a lot. The jetting is spot on too. Why does it smoke so much?

The guy told me it leaks a little oil from crankcase, but I dont think this could cause all the smoke I see. I am getting a lot of spooge out the silencer too, even though jetting is good.

Is it possible that the excessive smoke I see is from the oil leak from crankcase? Getting sucked into motor? I doubt it could be the collar/seal on clutch side because the leak is visible on the floor...

Any takes on this?

[Eddiesanders250]

excessive smoking means coolant.... this may not be the case for you but do yourself a favor and pull the plug and take a look.

[iamjasyn]

It's normal for them to smoke a lot when you first start them. If you've ridden it for over 5-10 minutes and still smoking hard, you likely have something extra getting into the combustion chamber.

If so, drain the coolant and open the head and see if you see water in the cylinder.

[beerock]

if the guy said the seal is leaking then its burning oil on the clutch side.

you can run it like this but its easy to replace the seal on the right side case., you might be able to get the seal off without splitting the cxases but it takes some finesse. even if you cant do that changing the right side seal is not that bad to replace you have to take the right side case off to replace it, but that case half is easy to take off since it slides into place and is not pressed on like the elft side case...


you can ride the bike like it is if in deed has a right side case crank seal leak BUT you risk blowing up the mtoor if you dont fix it soon.

for the record, oil burns blue and coolant burns white..

[ChvyCruzen]

Thanks for response guys.

The guy told me the oil leak is from case halves, not the seal.

I had my R warmed up and it was still smoking a lot. It's hard to tell if it's blue or white. I will check it again tomorrow.

I think I'll order new waterpump seals and bearings along with new collar and seal for the clutch side.

Are the bearings and seals the same for all years?

[86 Quad R]

another thing that i'd like to add is, regardless of whether or not it's leaking from the crank case or coolant, it can easily be identified by the smell of the exhaust. if tranny oil then it will have a smell like gear oil or similar.

do a leak down test to find out for certain as to where the engine is leaking.

[ChvyCruzen]

How do I perform a leak down test?

I thought I smelled more of coolant than gear oil - smoke was more white-ish than blue-ish.

[86 Quad R]

to do a leak down test you'll need to borrow or make your own tester such as this one....




it clamps into your intake boot and allows you to test the whole system.

you'll need to make a gasket that'll clamp between the exhaust flang and engine. my favorate is to use an inner tube from a bicycle.

as a rule of thumb, pump the system up (no more than 10 psi's and allow to set for at least 10 minutes.

during this time you spay the external engine with a soap/water mix to check for leaks. this includes the crank case vent tube aswell.

ideally you want the psi's to remain constant for the 10 minutes but a pound per minute is acceptable but not to exceed 5 lbs.

hope this helps

[ChvyCruzen]

That helps a lot.

Thanks